Petticoat pipe for boilers



E. J. REARDON PETTICOAI PIPE FOR BOILERS Oct. 19,1926.

2 Sheets-Shad. 1

Filed Dec. 5, 1924 nt? Film/rd .115011/1/012 I (j ('1 lleis I ll Oct. 19 ,1926. 1,603,804

E. J.'REARDON 'PETTICOAT PIPE FOR BOILERS Filed Dec. 5, 1924 z Shuts-Sheet 2 Inifenftc? Patented Oct. 19, 1926.

EDWARD J. REARDON, OF CHICAGO, ILLINOIS.

I'ETTICOA'I PIPE FOB BOILERS.

Continuation of application Serial No. 70338; filed June 2 1, 192 1. This applieation filed December 5, 1924. gerial No. 754,030.

My invention belongs to that general class of apparatus known'as draft devices, and relates more particularly to an improved petticoat pipe for locomotive boiler smoke boxes. The function of the petticoat pipe used in the short smoke box of a locomotive boiler is to equalize the draft through the tubes so that the draft is substantially the same in the bottom rows of tubes as in the center tubes. The invention has among its objects the production of a device of the kind described which is simple, compact, durable, efficient, reliable and satisfactory for use wherever found applicable. Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the disclosures herein given. 7

To this end my invention as disclosed in this application whichis a continuation of my priorapplication Serial Number 703,984, filed June 24:, 1924, consists the novel construction, arrangement and combination of parts herein shown and described, and

' more particularly pointedout in the claims.

In the drawings, wherein like reference characters indicate like or corresponding parts:

Fig. 1 is a longitudinal vertical section through a locomotive boiler embodying my improved petticoat pipe as arranged in the smoke box thereof.

; Fig. 2'isa. transverse vertical sectional view'tlirough the smoke box end of the boiler in the plane of thestack as indicated by the line 22 of Fig.1, the spark screen being omitted.

Fig.3 is a bottom plan view of the petticoat pipe shown in Figs. 1 and 2.

Figs. 4, 5 and 6 are views similar to Fig. 3 showing modified forms of my invention. :Iteferring now in detail to that embodi ment of the invention illustrated in Figs. 1 to 3 inclusive of theaccompanying drawingsz l indicates the shell of a locomotive boiler having a firebox 2 at its rear end and a smoke box 3 at its front end and associated with said smoke box is a stack 1 for discharging the products of combustion therefrom. Connecting the flue sheet defining the front end of'the firebox with the flue sheet defining the rear end of the smoke box are a plurality of fines 5 through which the products of combustion pass from the firebox to the smoke box in the manner well known, the front end of the smoke box being formed by the front plate 6. I l i i In the bottom portion of the smoke box, in alignment with the stack is the usual steam exhaust pipe 7 upon which is mounted a nozzle 8 of the desired type and size. Said nozzle discharges exhaust steam into the smoke box in line with the stack, thereby creating a draft through the firebox 2 and fines 5 which promotes combustion.

In Figs. 1, 2 and 3 I have shown a petticoat pipe or draft device 9, the function of which, as before mentioned, is to equalize the induced draft in the fines 5. This pipe may be supported by and may be connected to the stack in any suitable manner. As shown in said figures hereinabove mentioned, I provide a flange or collar 10 at the top end of the petticoat type and secure the same to the bottom end of the stack arranged in the smoke box by means of bolts 11. Either the top end flange or collar of the petticoat or the bottom end of the stack may be provided with a plurality of holes to receive the bolts 11 so that the petticoat pipe may be vertically adjusted relative to the stack a and nozzle 8. The petticoat pipe 9 as shown herein is particularly adapted for a relatively short smoke box and the front and rear wall portions extend substantially vertical while the sidewall portions preferably flare outwardly and downwardly from the top end or collar 10, as shown. Arranged within the petticoat pipe 9 is a similarly shaped but smaller auxiliary or supplementalpetticoat pipe '12, the Same being so constructed and positioned within the main or outer petticoat pipe as to provide a space 13 between said pipes which space extends from the top to the bottom of said pipes. As shown in Figs. 1 and 2, I preferably space the bottom edge of the inner petticoat pipe 12 in a plane above that of the outer petticoat pipe 9. The said petticoat pipes may be constructed in any suitable manner and are secured together by means of the bolts 14; and spacing sleeves 14E surrounding said bolts between said pipes in a manner holding them in the intended spaced relation. Of course, the construction just described is illustrative only and as many bolts and sleeves may be employed as is desirable.

I have found that in the single petticoat pipe heretofore in general use and which in ll u practice has had an efiective inlet area less than the area of the flues 5, there is a resistance to the flow of the products of combustion which is detrimental. My observation convinces me that this also results in a tendency to retard the flow of gases through certain tubes, thereby causing a relatively greater flow through certain of the other tubes which in turn results in unequal combustion conditions in the firebox. In my improved construction I preferably make the effective area of the intake end of the petticoat pipe at least substantially equal to the area oi the fines. Thus, the gases as they flow into the petticoat pipes are not greatly retarded because of the equal area of the conduit. lVhile the petticoat pipe is gradually constricted'toward the stack, it should be understood that this decrease of area is compensated for by a gradual increase in velocity which the exhaust steam causes as it discharges into the petticoat pipe. I also secure the most eil'ective use of the exhaust steam by making the outerpetticoat pipe as aclosed continuation of the stack 4. It is also'obvious that as the products of combustion and the exhaust steam pass upwardly they form a partial vacuum at the top of the inner pipe 12. "Therefore, in the event that some of the gases should, even with my improved construction, travel down the inner face of the inner pipe or shell 12 they will be drawn up through the space 13, by virtue of the aforesaid vacuum, and discharged through the stack instead of backing up in the smoke box.- By reason of the relative vertical spacing of the bottom edges of said petticoat pipes 9 and 12, such gases as pass down the. inner surface ofthe petticoat pipe 12 are guided or directed back into the space 13 and cannot pass the bottom end of the outer petticoat pipe and back up into the smoke box.

As will be observed, I space the bottom or lower edge of the petticoat pipe upward or above the tip of the exhaust nozzle so that there is a free passage for the flow of the productsof combustion from the'fiues and to the end that the effective inlet area of the petticoat pipe shall not be impaired. In this way a nice co-ordinatio-n of the functioning of the different boiler and firebox parts is produced.

The position of the petticoat pipermay be adjusted upwardly or downwardly until the draft is properly regulated, the fire in the firebox burning evenly at all parts when the proper adjustment is obtained. Experiments and tests made with the device under actual road conditions prove that the locomotive steams much better than with any device as used heretofore. there being no trouble in keeping the boiler hot, or in keeping a good even fire over the entire grate and this with a saving of fuel consumed. These tests demonstrate that the fire may well burn down before putting in another fire and that there is less clinkering with the device in use than without it.

In Figs. at, 5 and 6 I have illustrated modified forms or shapes of the bottom ends of the pipes 9 and 12. As shown in Fig. 1, 15 representsthe outer pipe, and 16 the inner pipe which has a discharge opening at the middle thereof. This construction is somewhat similar to that shown in Fig. 3 except that the sides are parallel or square instead of rounded. In Fig. 5, 17 and 18 represent the inner and outer spaced pipes which inner pipe has a discharge opening at the top end thereof. This is somewhat similar to the construction shown in Fig. 3 except that the bottoms of the pipes are more nearly oval, as shown in Fig. 5. In Fig. 6, 19 and 20 represent the outer and inner pipes, which inner pipe has the usual middle opening; in this case the pipes are circular at the bottom ends, the one concentric with the other. In all of these constructions, the conduit or space 13 exists between the petticoat pipes thereof regardless of whether the pipes are separable or are integrally connected, this being immaterial. The shapes or forms shown in Figs. 3 and 4 are generally preferred as the device is applicable for a comparatively short smoke box where there might not be room enough to install a de vice similar to that shown in Fig. 6. While the device is shown supported from the stack, obviously any equivalent or supplemental supporting means may be employed.

Before closing my specification I wish to state that tests indicate that the same etfec tiver velocity in the stack may be secured with a relatively larger nozzle as is secured in prior constructions with a relatively smaller nozzle. This is probably due to the fact that with my'constructi on it is possible to have the steam discharge into a smaller orifice (the inner'petticoat pipe) and yet remove the necessary volume of prodnets of combustion by virtue of the addi-. tional products of combustion that are siphoned in through the space between the inner and outer petticoat pipe. The-advantages of a larger nozzle opening on engine performance are too well known to require comment.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing fromthe spirit of the invention;

hence I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

I claim:

1. In a locomotive boiler smoke box device of the kind described and in combination with a stack and an exhaust nozzle, a

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flared petticoat pipe carried by the stack in closed communication therewith and projecting downwardly toward the nozzle with the flared end at the bottom, and an inner supplemental petticoat pipe arranged on the interior of the first-mentioned pipe and maintained in operative relation thereto, whereby smoke, steam and gases passing upwardly through the stack cause a draft through the space between the pipes.

2. In a device of: the class described, and in combination with a locomotive boiler, stack and steam nozzle, a plurality of spaced petticoat pipes arranged one within the other and tapering to the stack, one thereof being in closed communication with the stack, and means ad ustab1y securing said petticoat pipe so that its position relative to the steam nozzle may be changed.

3. In combination with a locomotive boiler smoke box, a steam nozzle and astack having an extension within the smokebox, a plurality of spaced petticoat pipes arranged the one within the other and positioned in the smoke box, one of said pipes being supported by and in closed continuation with the stack extension.

4-. In combination with a locomotive smoke box, a steam nozzle and a stack, spaced inner and outer petticoat pipes, with the outer one in closed continuation with the stack, the bottom edge of the inner petticoat pipe terminating in a plane above that of the bottom edge of the outer petticoat pipe.

5. In combination with a locomotive smoke box, a steam nozzle and a stack having an extension within the smoke box, a plurality of spaced inner and outer petticoat pipes arranged the one within the other and positioned in the smoke box, and means for adjustably securing the top end of the outer petticoat pipe to said stack extension within the smoke box.

6. In combination with a locomotive smoke box a steam nozzle and a stack, inner and outer spaced petticoat pipes positioned in the smoke box, the outer petticoat pipe being in closed continuation with the stack, the inner petticoat pipe having its bottom edge spaced in a plane above that of the bottom edge of said outer petticoat pipe.

In testimony whereof, I have hereunto set my hand, this 1st day of December, 1924.

EDIVARD J REARDON. 

